Ball release device for point detonating base fuze applications



Dec. 12, 1961 s. s. LINN 3,012,505

BALL RELEASE DEVICE FOR POINT DETONATING BASE FUZE APPLICATIONS Filed Sept. 21, 1960 mm x: W. 5 5

if @QZQJJMJQWMK Patented Dec. 12, 1961 This invention relates to a ball release device for a fuze and more particularly a ball release device for a base detonating fuze for a spin stabilized projectile.

In brief my invention comprises a fuze having a primer and detonator adapted for attachment to the base of a spin stabilized projectile. The fuze carries a ball which is held in safe position during flight, but which by its own inertia is moved to an outwardly extending groove upon impact. The ball then moves outwardly in the groove due to centrifugal force generated by projectile rotation and strikes a primer located at the outer end of the groove. The length of the groove may be varied in order to provide a varying time delay between impact and detonation.

It is an object of this invention to provide a fuze which is extremely simple and having only one moving part.

It is another object of this invention to provide a fuze for spin stabilized projectiles having an outwardly movable inertia element.

It is a further object of this invention to provide a fuze having a single movable member in the form of a ball which is activated upon impact.

It is yet another object to provide a fuze having an inertia element which is held in position against deceleration forces and released upon impact to move outwardly under centrifugal force to initiate detonation.

These and other objects will become more apparent when reference is had to the following detailed description and drawing in which:

FIGURE 1 is an axial sectional view of my invention showing the ball in the position assumed in flight FIGURE 2 is a sectional view taken on the line 2-2 of FIGURE 1 looking in the direction of v the arrows,

FIGURE 3 is a broken away sectional view showing a modification of the ball retaining means, and

FIGURE 4 is a broken away sectional view of another modification of the ball retaining means.

Referring now to the drawing and in particular to the embodiment illustrated in FIGURE 1, there is shown a conventional projectile 1 carrying the explosive charge 2 and threaded at its rearward end as at 3. The base etonating fuze includes a cup shaped housing 4 which is threaded to the rear end of the projectile 1 and carries the rotating or driving band 5. Received within the fuze housing 4 and rigidly secured thereto in any suitable manner, such as a force fit, is the plate or disk 6. The projectile and fuze have an axis of spin designated by the line AS. The disk 6 is provided with a hole 7 which is eccentric to the axis of spin AS. The forward end of the hole is provided with the lip 8. The ball 9 is received in the hole 7 in the plate.

Also received within the fun housing 4 is the plate or disk It} which abuts the disk 6. The disk 10 is provided with groove 11, the inner end of which aligns with the hole 7 in disk 6. The groove 11 extends radially outward and curves as shown in FIGURE and the outer end thereof is provided with the primer 12. The disk 10 is also provided with axial passage 13 which carries the detonator 14.

The operation of my fuze should now be evident. FIGURE 1 shows the position which the ball assumes during flight of the projectile. Inasmuch as the projectile is spinning, the ball 9 will move to the position which is farthest from the axis of spin. The lip 8 prevents the ball from creeping into groove 11 due to deceleration of the projectile in flight. When the projectile hits the target the inertia of the ball 9 will carry it over the lip 8 and into groove 11. From this point the ball will be propelled outwardly in the groove 11 by the action of centrifugal force until it strikes the primer 12. At this time the primer is initiated which fires the detonator 14 and explodes the projectile. It will be seen that the length of time required for the ball 9 to traverse the groove 11 will provide a time delay between impact and detonation. This time can be varied by changing the length and curvature of the groove.

FIGURE 3 illustrates a modified form of my invention. Similar reference numerals have been applied to parts corresponding to those in FIGURE 1. In this embodiment the bore 7 is provided with a counterbore 15. The ball 9' rides in this counterbore until the projectile strikes the target. At this time the inertia of the ball carries it out of the hole 7 into the groove 11 to then act in the same manner as in the embodiment of FIGURE 1.

FIGURE 4 illustrates a further modification of my invention. Again similar reference characters denote parts corresponding to those of FIGURE 1. In this embodiment the washer 16 is pressed into the disk 6 at the mouth of hole 7. The washer is of smaller inside diameter than the hole 7 so as to retain the ball during flight. Upon impact the ball rides over the washer 16 into the groove 11.

Instead of a primer being located in the groove 11 to be initiated by the ball 9 any other suitable means to be operated could be provided, such as apiezoelectric crystal, an electric switch or the like.

While I have shown and described various forms of my invention it will be apparent other modifications in construction and arrangement can be made without departing from the scope of my invention as defined in the appended claims.

I claim:

1. A fuze comprising a tubular housing for attachment to the rearward end of a spin stabilized projectile, a first disc secured in said housing, said first disc having a forwardly opening bore, said bore being'disposed eccentri-- cally to the longitudinal axis of spin of said housing, a second disc secured in said housing and disposed in abutting relation with and forwardly of said first disc, there being a groove in the rearward face of said second disc, said groove curving radially outward and having its inward end in alignment with said longitudinal bore in said first disc, a primer disposed near the outer end of said groove, there being a longitudinally extending passageway in said second disc and in registry with the outer end of said groove, a detonator in said passageway, a ball housed in said longitudinal bore in said first disc and means in said longitudinal bore for preventing said ball from creeping forwardly and out of said longitudinal bore during deceleration, said ball being movable out of said longitudinal J ore and into said groove upon impact force to detonate lid primer in said groove.

2. A fuze as set forth in claim 1 wherein the means in aid longitudinal bore in said first disc comprises an in- 'ardly diverging lip integral to the forward end of said mgitudinal bore and having a smaller inner diameter than 1e diameter of said longitudinal bore.

3. A fuze as set forth in claim 1 wherein the means in aid longitudinal bore in said first disc comprises a washer aving an inside diameter smaller than the diameter of 10 aid longitudinal bore, said washer being recessed in the )rward face of said first disc and coaxially with respect said longitudinal bore.

4. A fuze as set forth in claim 1 wherein the means in said longitudinal bore in said first disc comprises a counterbore disposed intermediate the length of said longitudinal bore, said counterbore having a diameter larger than said longitudinal bore, said ball normally riding in said counterbore.

References Cited in the tile of this patent UNITED STATES PATENTS 988,846 Abendroth Apr. 4, 1911 1,999,747 Aragone Apr. 30, 1935 2,304,106 Lake Dec. 8, 1942 2,837,999 Lindsay June 10, 1958 

